<p>A composite roasting method was used employing MnO₂ and MgO as additives to achieve efficient separation and recovery of vanadium from vanadium slag while enabling manganese and magnesium recycling. Under optimal experimental conditions, the roasting and leaching of the slag resulted in the recovery of 99.66% vanadium, along with 0.05% chromium and 0.09% iron. The ammonia gas produced during the vanadium precipitation step was used to adjust the pH of the vanadium precipitation wastewater for manganese and magnesium recovery. The recovered manganese and magnesium were reused as a roasting additive. After five cycles, the extraction efficiency of vanadium can still reach 96.57%. The wastewater generated by recycling magnesium and manganese can be used again in this process as a leaching medium. This recycling of experimental products reduces production costs while preventing environmental pollution. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses revealed that the high vanadium recovery is attributable to two synergistic effects: magnesium disrupts the iron olivine phase, and manganese combines with vanadium to form soluble vanadate.</p>